Do these always work? I installed one in my 96 explorer, which only has one downstream o2 sensor. I installed it and the p0420 code is back the same day. Barely 50 miles into driving (with one stop).

Is there any reason this would happen besides improper installation?

I had 4 wires coming off the sensor. 2 white (Unused) and a grey and a black. I connected the + to the grey and the - to the black. This matches what my haynes manual says as well.

Any help is appreciated, I'm trying to get this solved before I head out of town for a month and me Rejection sticker will expire (60 days).

Thanks

(I purchased on ebay from a user with all good pos feedback on these, so I'm sure they are average quality)

 

if you saying that the trick only has 2 wires for the o2 sensor, you cannot use a 4 wire O2 sensor in a 2 wire circuit.

 

I've never used any where you had to cut into the wires - the ones I have on my X are called O2 Simulators and they just plug in between the sensor and the wiring harness plugs. Haven't had a problem out of them. Seems like they were $40-$50 a piece from Summit....

 

The two wires are for the O2 signal and the ground. The other two wires on the sensor are used for Heater Power and Heater Ground. According to my instructions that I received with it. It does display the four wires in the instructions, but only two are used, this is similar to many I see online.

Any more help would be good.

Thanks